This invention relates to polymers derived from amines and hydroxy aromatic compounds, especially those suitable as Mannich Base dispersants, including conventional Mannich Base dispersants combined with such polymers. In the past, only the monomeric Mannich Base condensates have been available and these are limited to relatively low molecular weight/viscosity, except as adjusted by the size of the phenolic substituent, usually a polymer of 300-10,000 number average molecular weight (Mw). Journal of Polymer Science, Part A, 31, at pages 1955-1966 (1993) discloses a Mannich reaction of amines, formaldehyde, and phenols. Oil soluble hydroxyaromatic polymers are not taught. It has been found desirable to provide a polymeric Mannich Base additive whose viscosity/Mn can be adjusted by varying (especially limiting) the degree of polymerization rather than by changing the para substituent. The invention accomplishes this need and coincidentally, can also provide polymers with small or no para substituent which are useful as thickeners, viscosity agents, or antioxidants.
Various Mannich Base productions have suggested use of a broad range of components and conditions but none have been shown to produce the polymeric condensation adducts of the invention.